Objects that can both expand and contract would be ideal when it comes to space constraints where every inch counts. Origami, the Japanese ancient art of paper folding, seems to be a great source of inspiration to meet this objective. In fact, there are plenty of origami-inspired innovations in the fields of STEM (Science, Technology, Engineering, and Math). Origami is basically all around us — airbags, kayaks, ballistic shields, batteries, solar arrays, artificial muscles, and the list goes on. The application of origami in the medical field has been around for a while. Let us look at the two recent origami-inspired approaches to tackle medical challenges.
Medical patch for minimally invasive tissue sealing
Emerged in the 1980s, minimally invasive surgery is of high interest for interventional medicine. Meanwhile, tissue sealing and repairing remain a challenge for the surgeons due to limited visualization and degree of freedom. The current bioadhesives used in minimally invasive surgeries have limitations in terms of biocompatibility, sealing properties, and mechanical integrity. MIT researchers have thus come out with an origami-inspired medical patch to seal internal injuries.
In the form of a three-layered structure, this paper-like patch works by folding around the surgical tools. It will then transform into a stretchy gel and attach to the injured site once you press it against wet tissues or organs. The bottom layer consists of a material coated with silicone oil. It helps to prevent the patch from sticking to other surfaces prior to reaching the targeted wounded area. The top layer consists of an elastomer film embedded with zwitterionic polymers. Through the formation of a water-based skin, it serves as the barrier against bacteria and other contaminants. As for the main adhesive sandwiched between these two protective layers, it consists of a hydrogel material embedded with NHS esters.
The team had demonstrated the feasibility of this foldable medical patch on animal models of major airways and vessels. This included the trachea, oesophagus, aorta, and intestines. By folding this medical patch around a balloon catheter or a stapler, they then reached for the targeted injured tissues and organs. The adhesion of the medical patch was successful as they inflated the balloon catheter or exerted pressure to the stapler. There were no signs of contamination on or near the adhesion area (30 days post-application). Seeing this as an exciting approach to integrating bioadhesive into robotic surgery platform, the researchers are currently looking to collaborate with designers.
Robotic surgical assistant
We are seeing a rapid diffusion and adoption of robotic surgery. The da Vinci Surgical System became the first FDA-approved robotic surgical platform in the United States back in 2000 for general laparoscopic surgery. A cohort study (used data from the Michigan Surgical Quality Collaborative) showed an 8.4-fold increase in the use of robotic surgery for all general surgical procedures.
Downsizing, gravity compensation, and back drivability are among the obstacles of many robotic surgical assistants. Another concern is the trade-offs between stroke, actuating force, accuracy, and the power-to-weight ratio. This has thus led to the fruit of collaboration between Harvard’s Wyss Institute and Sony Corporation — miniature remote centre of motion manipulator (RCM). This mini RCM comes with a lightweight (2.4g) and miniaturized (50mm x 70mm x 50mm) design with three DOFs. Using the pop-up MEMS technique, this mini RCM can be assembled based on lamination and folding of several laser-cut materials. This forms a 2D starting plate that pops up into a 3D structure.
The researchers had carried out two user experiments as published in Nature Machine Intelligence. For the sub-millimetre-square tracing test, the RMS deviation from the desired trajectory was reduced by 68% compared to manual operation. The second test was a micro-cannulation test performed on a 0.2-mm-thick retinal vein phantom under a microscope. The results showed the mini RCM’s potential utility as a precise microsurgery tool to replace conventional RCM manipulators for teleoperated robotic procedures. In future, the researchers plan to increase the device’s actuating force, positioning precision as well as optimizing the trade-off between joint stiffness and spring back.
Possibilities lie between the folds
Origami is anything but ordinary. It is a great example of how art and technology can overlap, coexist, and influence one another. As more and more future designs might take origami into consideration, this folding art is likely to unfold a whole new field of innovation.
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